Pegasus is one of the deep multi-pay structures of the southern Midland Basin, straddling the Midland and Upton county line. It was opened at the end of the 1940s, and its distinguishing feature is vertical stacking: a single anticlinal closure with productive intervals ranging from the Spraberry down through Devonian carbonate to the Ellenburger, thousands of feet deeper. Fields like this are managed as several reservoirs at once, with different recovery mechanisms in each. For mineral owners, that means a tract can carry several separate producing interests.
Source: Texas Railroad Commission production filings, aggregated across RRC field designations 70279075, 70279100, 70279125, 70279250, 70279375, 70279500, 70279625, 70279750. Reported volumes lag the calendar by several months.
Midland County came late to production, with first oil in 1945 and the Midland South Pool success of 1947 establishing the region’s wealth in local terms. Upton County to the south had been producing since George B. McCamey’s 1925 wildcat opened the McCamey field, and the Benedum field arrived in 1947. By the end of the 1940s the ground between them was being drilled hard, with operators using improved rigs and electric logs to test structures far below the shallow Permian pays that had built the district.
Pegasus belongs to that deep-drilling wave. Structural closures in the southern Midland Basin frequently host stacked pay, because an anticline that traps oil in one interval will often trap it in others directly above and below. Development therefore proceeded interval by interval rather than all at once, with the deeper Ellenburger and Devonian zones drilled by fewer, more expensive wells and the Spraberry above them worked on much closer spacing. Each interval had its own operators, unit agreements and pressure history.
Recovery strategy varied by reservoir. Deep light-oil carbonates were supported by gas injection to hold pressure above the point where dissolved gas breaks out of the oil, while shallower intervals were waterflooded. The Spraberry has had a second life in the horizontal era, but that activity is a separate business from the deep conventional reservoirs and is usually held under different leases. Midland County production has fallen from nearly seventeen million barrels in 1956 to a fraction of that today, and the deep pays at Pegasus follow that trend.
Pegasus produces from a broad anticlinal structure in the southern Midland Basin with pay stacked through a very large vertical interval. The Ellenburger at the base is an Ordovician dolomite, fractured and karsted, sitting thousands of feet below the Devonian cherty carbonates above it; higher still, the Permian Spraberry is a tight interbedded sandstone and shale that behaves nothing like either. Each interval has its own porosity system, its own fluid properties and its own pressure regime, which is why they are developed and unitized separately rather than as a single reservoir.
Deep carbonate reservoirs at Pegasus have been supported by gas injection, which maintains pressure and preserves the mobility of light oil that would lose its dissolved gas if pressure fell. Shallower intervals have been waterflooded on conventional patterns. The Spraberry is a different problem entirely: it is tight enough that neither approach works well, and its modern development has come through horizontal drilling and hydraulic fracturing rather than through injection. Owners should not assume that activity in one interval says anything about the health of another on the same tract.
A Pegasus interest can involve several distinct income streams from one tract — deep conventional royalties under old unit agreements and Spraberry horizontal royalties under modern leases — with completely different decline profiles and valuation methods. Owners are frequently paid on some and not others without realizing it, particularly where the mineral estate was severed by depth. Because the field crosses a county line, separate decimals in Midland and Upton counties are also common. We buy minerals and royalties in Midland and Upton counties and provide free written offers.
County-level well data, production charts, and selling guides for the counties this field spans:
It means one tract can generate several separate royalty decimals, each tied to a different reservoir and often to a different lease, unit and operator. You may be paid monthly on one interval and not at all on another. The only reliable way to see the full picture is to reconcile every check stub and division order against the recorded leases on your tract.
They come from the same acreage but not the same reservoir. Spraberry production in this area is typically horizontal and hydraulically fractured, with high initial rates and steep decline. The deep Devonian and Ellenburger production is conventional, pressure-maintained and far flatter. They are valued on different methods and should never be blended into a single number.
Read the deed that created your interest and check whether it conveyed or reserved all depths, then trace every lease and depth severance recorded against the tract afterward. Depth-severed minerals are common in the Midland Basin because deep and shallow rights were often leased decades apart. We can review the instruments and tell you what you actually hold.